<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    
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 <style>
    /* 内部样式 */
    .ddddd {
        width: 400px;
        height: 400px;

        background-color: #ff0000;
    }
</style>

<!-- 外部样式表 -->
<!--
<link rel="stylesheet" href="./效果6.1.css">
-->









    <title>Document</title>
</head>





<body>
    



    <div class="ddddd" style="background-color:antiquewhite; width: 200px; height: 500px;">
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</body>
</html>